Golf balls are generally classified into two, one of which is a thread wound golf ball and the other is a solid golf ball. A representative example of the solid golf balls is a two piece solid golf ball which is composed of a solid center formed from vulcanized rubber and a cover formed on the center and made from thermoplastic resin.
Although the two piece solid golf ball has such a simple structure as mentioned above, it has very good performance in flight distance and durability and therefore has been approved by lots of amateur golfers. However, the two piece solid golf ball has high hardness and exhibits poor shot feel at the time of hitting and poor controllability at approach shot.
For improving the defects of the two piece solid golf ball, much effort has been paid and it has been proposed as the result of the study either that the core is made two layers or that the cover is made two layers. These methods improve the shot feel to some degree, but do not improve the other defects and the shot feel is also desired to be improved more.